package com.rabit.test;

import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;


public class CallableAndFuture {

	public static void main(String[] args) {
		ExecutorService threadPool = Executors.newSingleThreadExecutor();
		Future<String> future = threadPool.submit(new Callable<String>() {

			@Override
			public String call() throws Exception {
				Thread.sleep(2000);
				return "Hello";
			}
		});
		System.out.println("等待结果");
		try {
			System.out.println("拿到的结果"+future.get());
		} catch (InterruptedException e) {
			e.printStackTrace();
		} catch (ExecutionException e) {
			e.printStackTrace();
		}
		ExecutorService threadPool2 = Executors.newFixedThreadPool(10);
		CompletionService<Integer> completionService=new ExecutorCompletionService<Integer>(threadPool2);
		for (int i = 0; i < 10; i++) {
			final int seq=i;
			completionService.submit(new Callable<Integer>() {
				
				@Override
				public Integer call() throws Exception {
					Thread.sleep(new Random().nextInt(5000));
					return seq;
				}});
		}
		for(int i=0;i<10;i++){
			try {
				System.out.println(completionService.take().get());
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (ExecutionException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
	

}
